Microstructure, hardness and cavitation erosion resistance of different cold spray coatings on stainless steel 316 for hydropower applications

Journal Article · Tue Dec 01 00:00:00 EST 2020 · Materials Today Communications

DOI:https://doi.org/10.1016/j.mtcomm.2020.101305· OSTI ID:1708856

Jiang, Xiujuan ^[1]; Overman, Nicole R. ^[1]; Smith, Christopher B. ^[1]; Ross, Kenneth A.  ^[1]

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1. BATTELLE (PACIFIC NW LAB)

There is an urgent need for repair of hydropower components that have undergone damage due to cavitation. Conventional repair methods involve melting of materials and can deteriorate material properties and cause distortion. This study investigated the relevant properties of different materials using solid phase processing—cold spray technology. Stainless steel (SS) 316, Inconel 625 and CrC-NiCr materials were cold spray deposited onto base metal SS 316, respectively. Cold spray achieved dense uniform deposits with low level porosity, and intimate contact between the deposit and the base metal was observed. Severe plastic deformation imparted during the cold spray process resulted in significant grain size refinement, nanostructured regions were observed in the deposits across the interfacial area. Cold sprayed deposits exhibited elevated hardness in contrast to that of the base metal SS 316. The cavitation erosion resistance of the deposits was evaluated with a cavitation erosion jet adhering to ASTM G134. Both SS 316 and Inconel 625 achieved better cavitation erosion resistance when compared to that of the SS 316 base metal, with the former exhibiting close to a 4 times improvement.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1708856
• Report Number(s): PNNL-SA-143343
• Journal Information: Materials Today Communications, Vol. 25
• Country of Publication: United States
• Language: English